1. Field of the Invention
This invention relates to methods, systems, apparatus and a rotor for metering, conveying and dispensing granular materials and/or liquids and, in particular, to methods, systems, apparatus and a rotor for metering, conveying and dispensing granular materials onto a plurality of zones and/or liquids onto a plurality of regions.
2. Description of Related Art.
Various forms of devices for applying particulate or liquid pesticides or the like are known. These can comprise structures for mounting on a motorized vehicle or a pull-type vehicle.
U.S. Pat. No. 4,630,773 discloses a device for spreading granular fertilizer, liquid herbicide and liquid insecticide. The device is on a motorized vehicle and has a plurality of product bins and liquid tanks. Feeder devices meter granular products from the bins under computer control onto a conveyor through a single rotary spreader onto an area of the ground. Such devices spread material on a relatively narrow strip of ground generally requiring multiple passes by the vehicle.
U.S. Pat. No. 4,569,486 discloses a pneumatic device for distributing particulate material such as fertilizer, herbicide or seeds on a pull-type vehicle with booms which extend to one or the other side of the vehicle. Such devices are useful on open territory such as farmland. However, the vehicle cannot pass near obstructions like signs, poles or trees without altering the position of the booms requiring either a change in vehicle path to avoid the obstructions or time and effort to change the position of the booms.
Such devices are designed to apply numerous products, such as seeds, fertilizers, pesticides including herbicides, insecticides and fungicides, and other agricultural chemicals. The product per unit area dispensing rate varies greatly depending on the product being applied. The pesticides typically applied in the past have active ingredient concentrations of about 15% or less by weight. This requires such pesticides to be applied at high product per unit area rates, such as greater than 10 pounds per acre (11.2 Kg/ha) and more typically 20 to 30 pounds per acre (22.4 to 33.6 Kg/ha). Other products, such as fertilizers, often require application rates of several hundred pounds per acre. Since previous product application rates are so high, the dispensing devices have not needed to be able to accurately meter and uniformly apply small quantities of dry granular material.
There are granular materials available having about 60% to about 80% concentration by weight of active ingredients. Some of these materials need only be applied at rates of a fraction of an ounce per acre to about one pound per acre, such as Oust.RTM., Escort.RTM. and Telar.RTM., all commercially available from E. I. du Pont de Nemours and Company with offices in Wilmington, Delaware. Other of these materials need only be applied at about one pound per acre (1.1 Kg/ha) to about 10 pounds per acre (11.2 Kg/ha), such as Karmex.RTM. and Krovar.RTM., both also available from E. I. du Pont de Nemours and Company. See U.S. Pat. Nos. 4,127,405, 4,383,113, 4,394,506, 4,481,029, and 4,420,325 for a further description of sulfonylurea herbicides which are granular materials that can be applied at application rates less than about 10 pounds per acre (11.2 Kg/ha).
In the past, products, such as pesticides, were frequently applied to the ground with liquid, such as water, for many reasons. Dry granular materials are frequently pulsed through metering devices resulting in an uneven application of the product on the ground. Dry granular materials are easily broken up in systems causing the product to be more easily blown away by the wind once released from the dispensing system. Existing devices can not apply product far, i.e., greater than about 10 or 20 feet, from a point of release on a dispensing vehicle without spraying the product in a liquid form. However, carrying the liquid reduces space for the actual product and, thus, increases application costs.
In view of the high concentrate granular materials available today and the cost savings associated with applying a product in granular form, it is desirable to provide a system for applying products in the form of dry granular material(s) at low application rates including less than 10 pounds per acre (11.2 Kg/ha) to as low as about one ounce per acre (1.1 Kg/ha).
Unique needs exist in applying pesticides near railroad tracks. For instance, different pesticides may best be applied on different zones or regions that vary with distance from the centerline between the railroad tracks. It is also desirable to have the ability to apply different rates of the same or different product(s) to different zones along the tracks. At certain locations along tracks, such as near intersections with roads, it is desirable to apply pesticides on wider strips of land from the tracks than other track locations. Obstructions, such as signs, trees, fences and poles, are common along railroad tracks making the use of extended booms impractical.
Therefore, it is desirable to provide a boomless system for applying products in the form of dry granular materials, especially along railroad tracks, where different products can be applied at different rates on different zones substantially without pulsing or attrition of the material.
However, some products may only be available in liquid form or, for some reason, it may be preferred to apply a product in liquid form. Therefore, it is desirable to provide a system for applying at least one dry granular material at rates less than about 10 pounds per acre (11.2 Kg/ha) to about one ounce per acre (1.1 Kg/ha) without pulsing or attrition of the material onto a plurality of zones and/or at least one liquid onto a plurality of regions.